Focus Report: PCB Design Tools

Whether Marie Antionette's infamous decree "Let them eat cake" to reports of starving subjects is true or not, a similarly apathetic response, "Let them ignore signal integrity," could be imagined to describe advice that printed circuit board (PCB) engineers and designers can't afford to take. Signal integrity problems are among the many consequences PCB engineers (those who layout the board) and designers (those who route the wires) have experienced as a result of the increasingly high-speed components and the corresponding high-speed signals that are being integrated into PCB design. Though board engineers and designers are enjoying less components on a board, partly because of the system-on-a-chip (SOC) push in the chip design world, these same components are requiring PCB design tools that can handle, among other things, signal integrity issues that result from faster clock rates, RF functions, analog functions, and an increased knowledge of the packaging surrounding the components. Moreover, mainstream PCB tool users are finding use for these functions in their designs today-not just the "power" or high-end users who were purchasing these tools in recent years.

In correlation to the evolution of PCB tools and their user base, the PCB market is transforming. In the last several months, the collective sales revenue of PCB tool vendors has swelled prosperously. As printed in a recent EDAC (Electronic Design and Automation Consortium; San Jose) Market Statistics Service Report, the total worldwide sales for PCB and MCM Layout (including licensing and maintenance) through the first three quarters of 2000 was $307 million. This is a 28 percent increase when compared to the $239 million of PCB and MCM sales through the first three quarters of 1999. (1999 showed $330 million in revenue for all four quarters.) This bounty, however, has also corresponded with a drastic change in the makeup of the PCB tool industry.

Since March 1999, the last time ISD Magazine ran a similar report ("Focus Report: PCB and MCM Tools" March 1999, p. 48), seven companies in the PCB sector have either been acquired (March 1999, Xynetix by Avanti; July 1999, Orcad by Cadence; November 1999, Veribest by Mentor; January 2000, Accel by Protel; March 2000, Incases by Zuken), merged (September 1999, Viewlogic and Summit Design into Innoveda), or merged and then acquired (September 2000, Pads acquired by Innoveda).

What do users make of the rise in complexity and the consolidation? Is this a cause for worry?

According to Mark Singleton, a senior design engineer at Intel Corp., change is a constant in the PCB world. Singleton uses the example of a telephone modem he helped design to illustrate the many cultures PCB design must exist in and how it differs from the IC world. "The modem, which we started in December 1999 had to produce 50K boards by the end of the year. We finished by May and went into production in June 2000. We then got the call there was to be an addition to the boards, so we had to spin the boards three more times and pick up multiple footprints from different suppliers because there simply wasn't enough parts from one supplier to make the board. In the IC world, the designers would only have to go to one or two suppliers-this isn't true in the PCB world." Singleton's example shows how PCB engineers often must look past the CAD stage of a design to the bigger picture, that includes interacting with suppliers and manufacturing. Parentherically, PCB designers often rely more on their experience when routing a desgin rather than on the automated functions of the tool set they're using. A refreshing consequence of this is that many of the good PCB designers are considered artists in their own right, each bringing a personal style to each board.

Similar worlds

The differences between the interconnected worlds of PCB and chip design aside, the two worlds have many similarities as noted by David Wiens, vice president of product marketing for board products at Mentor Graphics Corp. (Wilsonville, OR). "Both [PCB and chip design] can be defined with HDLs or schematics (but PCBs are still predominantly schematic-based); both involve similar placement and floorplanning and routing tasks; and both are plagued by the same timing and signal integrity problems."

Mentor's PCB tools reflect Wiens' comments, as their Boardstation (from Mentor, part of their Workgroup product family) and Expedition (formerly Veribest's technology, now part of Mentor's Enterprise product family) products both support verification, a technology that is a core function in the chip world and is becoming increasingly necessary in PCB design. Both Board Station and Expedition are PCB design environments that have similar core functions like design capture, floorplanning, and place and route.

Though both tools are supported by the same engineering and management teams, Expedition is geared for smaller organizations while Boardstation includes library management functions that, Wiens says, can "partition the design into logical sub-circuit blocks. The blocks may then by designed concurrently by an engineering team. When the blocks are completed, a merge process resolves any conflicts, and creates the final PCB ready for manufacturing." According to Wiens, in the next several months Boardstation is earmarked to support remote collaboration by way of a multi-site data distribution function that will allow teams to merge data libraries globally.

As designers will work closer together in the future, regardless of location, so internationally based PCB tool vendors are attempting to get closer to the U.S. PCB design market. DDE A/S, the American arm of which is DDE-USA, is a PCB layout tool company founded in 1975 and based in Denmark. Though most of their business currently comes from Europe, the company is beginning to push their layout tool, Supermax E-CAD, into the U.S. market. According to technical manager Per Viklund, Supermax E-CAD is, "a layout solution that is designed to handle PCB, MCM, hybrids and advanced packaging in the same tool." Though the tool lacks a schematic design or simulation environment it can plug into schematic and simulation tools from other companies like Cadence or Innoveda.

Aimed at the high-end user group, Supermax supports analog, digital, advanced RF, and microwave design functions. According to Viklund the nature of PCB tools is changing, as even simple designs, because of faster edge rates, become high-speed designs. "The schematic is not just the schematic anymore but more a design entry and exploration tool that you hook up to a constraint manager and various analysis tools...there is a long way to go before routing."

Another international PCB tool vendor, Electronics Workbench (Toronto, Canada), claims to be the market leader in the PCB software arena by virtue of their 150,000 customers worldwide. President Bob Wignall says that their schematic capture and simulation, layout, and routing tools-Multisim, Ultiboard, and Ultiroute respectively-enjoy this kind of popularity in part because of the unique relationship they have with academia, where they design product features specifically for educational and training centers.

Additionally, Wignall sees simulation as a core part of the PCB design flow, occurring after schematic capture, and before autorouting. Wignall is confident more PCB designers will use simulation in the future. "One of the biggest reasons PCB designers resisted simulation was that companies couldn't simulate the critical path parts. [Multisim] does this through cosimulation." Multisim also offers a component library with simulation models that can be updated through a proprietary link (access is gained only through use of the tool) to edaparts.com.

It is perhaps because of this increased international presence and the newer and cheaper tool selection that comes with it, that many of the U.S.-based tool vendors have recently increased the spate of cannibalism amongst themselves.

PCB tool guru Lee Ritchie, a noted PCB and system design consultant and teacher, whose tenure in the industry stretches back for several decades, uses the term "acquisition parade" to skeptically describe the recent mergers and acquisitions. "Most of [the acquisitions] are motivated by the parent company having a deficiency in some tool area, so they buy tools that are known to be good. Problem is, the acquiring company nearly always degrades the tools that they purchase and we are out a good tool. It is rare that these acquisitions improve the tool base."

Taking a different point of view on the consolidation front, analyst Rita Glover, president of market research firm EDA Today, is optimistic about the opportunity for PCB tool users. "I think the tool quality will improve, because the consolidation will create a more concentrated set of tool developers and fewer tool formats to support. PCB tools were becoming commodity items and a consolidation had to occur for PCB tools to get to the next generation."

Two steps to success

Ultimately, Ritchie cites two factors when determining the success of any tool. "The companies that produce good tools have two things in common. They have a good technical staff and they actually work in the field on real designs. Cadence with their design group is the best example."

Jamie Metcalfe, vice president of marketing for PCB Systems at Cadence (San Jose), shares his view of consolidation as applied to Cadence. "PCB vendors merge and end up having to kill off overlapping products. (We have not had this problem with the Orcad and CCT [acquired in May '97] acquisitions.)" Similar to the manner in which Veribest exists within the Systems Design Division of Mentor Graphics, Orcad now operates within the PCB Systems Division (PSD) of Cadence, which merges the existing Cadence PCB team and products (PCB Design Expert and Specctraquest) with the Orcad team and products (Orcad layout).

Orcad layout, according to Metcalfe, is still intended for the mainstream PCB design group "Orcad products normally come into play with the EE who does everything, often when prototyping systems...while the Cadence PCB products such as PCB Design Expert and Specctraquest are used in a team design environment." Specctraquest is a design environment with four substantial components-a floorplanner/editor, topology exploration environment, simulation subsystem, and autorouter. Cadence's other PCB suite, PCB Design Expert performs capture and layout functions and consists of a combination of Cadence and Orcad technology including-Orcad's schematic capture tool, Capture CIS, Cadence's schematic capture tool, Concept HDL, and Cadence's Allegro layout tool.

Out of all the PCB tool vendors, Innoveda has the most legacy of change. Rick Almeida, former vp of marketing at Pads and now vp of marketing for the product realization group at Innoveda, explains the relationship between Pads' (now Innoveda's) Power PCB design environment and Blaze Router, an autorouter that's also legacy technology from Pads. "Power PCB and Blaze Router are two separate tools. However, Blaze Router's purpose is to provide an autorouting function for Power PCB so you could consider Blaze Router to be a sub application of Power PCB." Almeida describes Power PCB as an environment that provides interactive parts placement and routing, post-layout checking, documentation and manufacturing outputs. Almeida also elaborates on the XTK signal integrity tool that originated from Viewlogic and Pads' signal integrity tool, Hyperlynx. "The difference between Hyperlynx and XTK is that Hyperlynx is easier to use, targeted at the mainstream electrical engineer, and is very interactive. XTK has very exhaustive simulation capabilities, and is targeted at the signal integrity expert." Almeida suggested that XTK and Hyperlynx will soon be merged into a single product, one that could be part of the Power PCB tool suite.

If merging is the constant within the PCB tool vendor industry, what is the model for the in-between space sitting amidst PCB design and chip design? It's definitely apparent that there's little such space any longer. Ritchie brings up an appropriate example. "MOS circuits are so fast now that when they drive a transmission line they give off bad reflections; this requires the chip designer to place a resistor in the output of the driver (called a series termination). A memory chip has 32 lines. This equals 32 resistors.

If a [PCB] engineer tries to put this on the circuit board, there won't be enough room. A chip designer must be aware of this."

Viklund also shares similar sentiments with Ritchie. "We are still designing chips as if [they are] an end product and then use the chips on a board later. That is obviously rather silly as every chip will have to be put on some kind of 'component carrier' sooner or later and in that process, a lot can be gained if it is coordinated properly."

No designer or engineer, in the chip or board space, is omniscient, nor can they anticipate every challenge a design will face after it passes through the myriad hands required to bring it to eventual end-product status. As such, these notions, if valid, are probably more than PCB tool vendors can answer alone.